Office Of Science Research Articles

Materials Mitigation Strategies and Anode Catalyst Durability in Low Temperature Electrolysis

Hydrogen has unique advantages as an energy carrier, with a high energy density and capacity to facilitate both long term storage and conversion between electricity and chemical bonds. Although hydrogen currently has a significant role in transportation and agriculture, its use in the general energy landscape has been limited. With decreasing electricity prices, electrolysis cost reductions can be achieved and will enable an opportunity for greater use.[1] While load-following renewable power sources can reduce feedstock costs, further cost reductions can be achieved by reducing the platinum group metal (PGM) content.[2]Efforts are needed and underway to understand electrolyzer degradation and develop accelerated stress tests when accounting for lower PGM loadings and intermittent operation. In this presentation, studies related to different catalysts and catalyst layer properties, and their impact on electrolyzer performance and durability will be discussed. Catalysts with high metal content and less stable elements were generally found to be more susceptible to mobility and migration.[3] Materials have been evaluated, however, that can address catalyst degradation. These include catalyst development strategies such as crystallinity, structured morphologies, and supports, and electrode design strategies such as coating techniques and pore formers. In some cases this has led to increased site utilization and the spread of operational stressors through a larger portion of the catalyst layer, lessening performance losses over time. Testing of these materials has included more continuous operation and with applied accelerated stress tests, and it was found that certain materials may address load fluctuations in different ways. Perspectives on anode catalyst development will be discussed as they relate to the current status of materials mitigation strategies and anode catalyst layer degradation.[1] B. Pivovar, N. Rustagi and S. Satyapal, The Electrochemical Society Interface, 27, 47 (2018).[2] K. Ayers, N. Danilovic, R. Ouimet, M. Carmo, B. Pivovar and M. Bornstein, Annual Review of Chemical and Biomolecular Engineering, 10, 219 (2019).[3] Pivovar, B. S.; Boardman, R., H2NEW: Hydrogen (H2) from Next-generation Electrolyzers of Water. 2022.Acknowledgements: This research is supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office under the auspices of the H2NEW consortium. Electron microscopy was performed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility at Oak Ridge National Laboratory. The X-ray spectroscopy experiments were performed at beamline 10-ID at the APS, which is operated by the Materials Research Collaborative Access Team (MRCAT). MRCAT operations are supported by the Department of Energy and the MRCAT member institutions. The APS is a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

Probing the Effect of Environments on the Stability of Ni2P Nanoparticle Electrocatalysts

Ni2P has been shown to be an effective catalyst for the hydrogen evolution reaction (HER), making it a promising replacement for Pt which is the current state of the art HER catalyst.1,2 H2 is a clean-energy critical fuel and chemical highlighted by the US Department of Energy’s “Hydrogen Shot,” which seeks to reduce “the cost of carbon-neutral hydrogen by 80% to $1 per 1 kg in 1 decade, highlighting the key role of hydrogen in implementing carbon-neutral solutions.”3 Ni2P is also a good or promising catalyst for other reactions, such as alcohol oxidation, hydrodesulfurization,4,5 nitrate reduction, and oxygen evolution reaction.6 However, Ni2P and other TMPs are susceptible to oxidation, which can lead to catalyst degradation and loss in certain conditions.7,8 Stability is an important part of catalysis, especially for achieving the goals of the Hydrogen Shot. Therefore, it is important to understand complex degradation mechanisms in order to better understand structure-activity relationships in these materials. In the present work, in situ Ni K-edge X-ray absorption spectroscopy (XAS) and ex situ P Kα and Kβ X-ray emission spectroscopy (XES) couple together to understand the degradation of Ni2P and show the effects of electrolyte pH, ligands, and air on Ni2P nanoparticles.5 nm Ni2P nanoparticles were synthesized by heating NiCl2 and tris(diethylamino)phosphine in oleylamine. The nanoparticles were drop cast onto carbon fiber paper electrodes and Si wafers or Au-coated wafers for P Kα and Kβ XES. Oleylamine ligands are removed by thermal annealing. Electrochemical experiments were conducted with a three-electrode cell using carbon fiber paper or Au-coated wafers deposited with Ni2P nanoparticles as working electrode, Ag/AgCl calibrated to the H2 redox couple as reference electrode, and graphite rod as counter electrode. P Kα and Kβ XES experiments were conducted inside a N2 glovebox to prevent unintentional air oxidation. Transmission-mode Ni K-edge XAS was conducted on a benchtop spectrometer.Upon exposure to air, as-synthesized Ni2P nanoparticles were studied via P Kα and Kβ XES. Results showed that the phosphide species converted to phosphate with analysis of intermediates well fit by a simple two-phase mixture. Phosphide:phosphate ratios were quantified using linear combination analysis, providing a powerful tool to analyze P speciation on various samples in an inert environment and with minimal loss of material, both advantages of this system over 31P magic angle spinning solid state nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy. Continued work looks at analyzing the effects of the ligand environment on the stability of nanoparticles in electrolytes spanning from acidic to basic pH. We hypothesize that ligands will significantly stabilize the nanoparticles against corrosion and that without ligands Ni2P readily converts to a nickel phosphate species upon exposure to electrolyte.References(1) Popczun, E. J.; McKone, J. R.; Read, C. G.; Biacchi, A. J.; Wiltrout, A. M.; Lewis, N. S.; Schaak, R. E. Nanostructured Nickel Phosphide as an Electrocatalyst for the Hydrogen Evolution Reaction. J. Am. Chem. Soc. 2013, 135 (25), 9267–9270. https://doi.org/10.1021/ja403440e.(2) Liu, P.; Rodriguez, J. A. Catalysts for Hydrogen Evolution from the [NiFe] Hydrogenase to the Ni2P(001) Surface: The Importance of Ensemble Effect. J. Am. Chem. Soc. 2005, 127 (42), 14871–14878. https://doi.org/10.1021/ja0540019.(3) Bullock, M.; More, K. Basic Energy Sciences Roundtable: Foundational Science for Carbon-Neutral Hydrogen Technologies (Report); DOESC Office of Basic Energy Sciences, 2022. https://doi.org/10.2172/1834317.(4) Layan Savithra, G. H.; Muthuswamy, E.; Bowker, R. H.; Carrillo, B. A.; Bussell, M. E.; Brock, S. L. Rational Design of Nickel Phosphide Hydrodesulfurization Catalysts: Controlling Particle Size and Preventing Sintering. Chem. Mater. 2013, 25 (6), 825–833. https://doi.org/10.1021/cm302680j.(5) Rodriguez, J. A.; Kim, J.-Y.; Hanson, J. C.; Sawhill, S. J.; Bussell, M. E. Physical and Chemical Properties of MoP, Ni2P, and MoNiP Hydrodesulfurization Catalysts: Time-Resolved X-Ray Diffraction, Density Functional, and Hydrodesulfurization Activity Studies. J. Phys. Chem. B 2003, 107 (26), 6276–6285. https://doi.org/10.1021/jp022639q.(6) Menezes, P. W.; Indra, A.; Das, C.; Walter, C.; Göbel, C.; Gutkin, V.; Schmeiβer, D.; Driess, M. Uncovering the Nature of Active Species of Nickel Phosphide Catalysts in High-Performance Electrochemical Overall Water Splitting. ACS Catal. 2017, 7 (1), 103–109. https://doi.org/10.1021/acscatal.6b02666.(7) Ha, D.-H.; Han, B.; Risch, M.; Giordano, L.; Yao, K. P. C.; Karayaylali, P.; Shao-Horn, Y. Activity and Stability of Cobalt Phosphides for Hydrogen Evolution upon Water Splitting. Nano Energy 2016, 29, 37–45. https://doi.org/10.1016/j.nanoen.2016.04.034.(8) Parra-Puerto, A.; Ng, K. L.; Fahy, K.; Goode, A. E.; Ryan, M. P.; Kucernak, A. Supported Transition Metal Phosphides: Activity Survey for HER, ORR, OER, and Corrosion Resistance in Acid and Alkaline Electrolytes. ACS Catal. 2019, 11515–11529. https://doi.org/10.1021/acscatal.9b03359.

Free Institutional Internet References and the Language of Covid-19

The present paper is concerned with the inclusion in free English-language institutional internet reference works of terms used to discuss health, disease, treatments and medical breakthroughs in the context of COVID-19. The focus is on the glossaries that are available on the websites of the UK Parliament and UK Government, i.e. on credible and authoritative platforms that are in various ways intended to serve as seats for asymmetrical transfer and mediation of knowledge about their operations and services (Engberg & Luttermann, 2014): Coronavirus (Covid-19) Definitions is the online interactive glossary published by the Office of National Statistics in 2022; the COVID-19 glossary is published by the Parliamentary Office of Science and Technology (POST). Cross-verification of wordlists and lexicographical treatment in selected dictionary entries is carried out vis-à-vis free and unlocked content from the Oxford Reference platform and the English Wiktionary. Integrating insights from the Function Theory of Lexicography (Bergenholtz & Tarp, 1995), and Wiegand’s (1977 ff.) Actional-Semantic Theory of Dictionary Form, we are able to demonstrate that Coronavirus (Covid-19) Definitions and the COVID-19 Glossary provide basic answers to the queries of lay users – which is in line with the government’s social responsibility to pursue health promotion, prevention of ill health and health protection.

Obturator hygiene among patients with maxillary defects at two teaching hospitals in Ghana

Background: An obturator may be defined as the component of a prosthesis that fits into and closes a defect within the oral cavity or other body defects. Cleaning one’s obturator is essential to prevent offensive odour, poor aesthetics, the accumulation of plaques, and damage to both natural and prosthetic teeth due to bacteria contamination in the oral cavity.Aim: The study aimed to determine how palatal obturator wearers practice good obturator cleaning habits.Method: A cross-sectional study design was used for this study. A sample size of 40 palatal obturator wearers was used. Data was collected using a well-structured questionnaire. The questionnaire included demographic data (age, sex, educational level, occupation and years of wearing a prosthesis, obturator cleaning habits, obturator cleaning methods, and obturator wearing habits. The data were summarized using Descriptive statistics with tables and charts and analyzed using a chi-square test from Statistical Package for Social Sciences (SPSS version 22.0) and Microsoft Office Excel 2016 at p-value< 0.05.Results: Sixteen (40%) of the total number were males, and 24(60%) were females giving a male-to-female ratio of 2:3. Twelve (30%) of the participants fell between the ages 31-40 years. Participants with tertiary education have better cleaning habits and knowledge of cleaning agents used. Fifteen (37.5%) participants who had worn a palatal obturator between 1-2 years frequently visited the dental clinic for a check-up; however, this number gradually decreased.Conclusion: The majority of the patients evaluated had good clean habits with their prostheses and the cleaning agents used. However, participants with tertiary education had better prosthesis hygiene and maintenance methods.

Recent H- ion source research and development at the Oak Ridge National Laboratory* *This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). This research was supported by the DOE Office ofScience, Basic Energy Science, Scientific User Facilities. The US government retains and thepublisher, by accepting the article for publication, acknowledges that

The U.S. Spallation Neutron Source (SNS) is a state-of-the-art neutron scattering facility delivering the world's most intense pulsed neutron beams to a wide array of instruments which are used to conduct investigations in many fields of science and engineering. Neutrons are produced from spallation of liquid Hg by bombardment of short (∼1 μs), intense (∼35 A) pulses of protons delivered at 60 Hz by a storage ring which is fed by a high-intensity, ∼1 GeV H- LINAC. This facility has operated almost continuously since 2006, with ion source performance increasing over those years, and currently providing 50–60 mA of H- ions with a duty-factor of 6% for maintenance-free runs of several months with near 100% availability. Ion source research and development at ORNL has played a key role in enabling and supporting this success: this report provides an update on some of the ongoing ion source research and development efforts which have been undertaken since the previous Negative Ion Beams and Sources (NIBS) conference in 2020. These include significant improvements to H- beam current by extraction from a larger source outlet aperture and improvements to the electron dumping system which should eliminate the gradual loss of electrode voltage over the course of a run which has occasionally impacted SNS operations. Improvement and simplification of the plasma ignition system for the external antenna ion source, a long-standing problem, was also realized. Lastly, RF coupling efficiency was measured for both the SNS internal and external antenna ion sources.

Современные процессуальные подходы в уголовном, гражданском и арбитражном судопроизводстве РФ

The relevance of research. The paper analyzes the heading “Mainstream issue” of the current issue of the journal “Legal Concept = Pravovaya Paradigma” “Procedural law technologies for preventing offenses and combating crime”. The prepared issue deals with the problem of modern procedural approaches and the methods of procedural communication in civil, arbitration, and criminal proceedings, modernized by the procedural reform of 2018–2022. The paper highlights the factors of modern reality that necessitated the inclusion of legal science, legislator, and law enforcement officer in the process of actively seeking a balance between a wide variety of procedural approaches and the methods of procedural communication. The scientific and practical significance of the papers presented in the heading is analyzed. The scientific novelty of the conducted comprehensive intersectoral legal research, which has made up the content of the heading “Mainstream issue”, is based on the results obtained by the authors of the scientific papers touching on various aspects of the consequences of the procedural reform, which was initiated by the draft law proposed by the Supreme Court of Russia and followed by Federal Law No. 451-FZ of November 23, 2018 “On Amendments to Certain Legislative Acts of the Russian Federation”. The fundamental changes that the “procedural revolution” entailed were reflected in more than 20 federal laws and influenced the transformation of established approaches in civil, arbitration, criminal and administrative proceedings, as well as the order of the judicial system as a whole. Many of the most controversial issues related to both traditional and modernized procedural regulation under the influence of digitalization and scientific and technological progress are also analyzed. The methodological framework for the intersectoral legal research has traditionally been made up of general scientific methods of cognition used in the social sciences and humanities in general, including in law. Among the most significant general methods of cognition are the method of historical materialism, as well as the general logical methods: analysis, synthesis, induction, deduction. The special and private methods are presented in the scientific papers of the heading mainly by formal legal and comparative legal methods. Results. It is revealed that some of the most important topics of judicial proceedings remained untouched by the reform, although they were repeatedly raised both within the framework of doctrinal discussions and in the process of developing legislative initiatives. In this connection, their coverage in the framework of scientific papers prepared under the heading “Mainstream issue” remains relevant. Conclusions. Taking into account the opinion of specialized professionals, as well as based on the analysis of the legislative novelties, the conclusion is substantiated that the main purpose of the changes introduced through procedural reforms both in Russia and abroad is the unification of procedural law. As another fundamental reason, the author cites the optimization of legal proceedings caused by the processes of digitalization of all spheres of public life and the creation of a new order of procedural communication. It is established that many controversial issues related to the current procedural approaches, not affected by the reform, have received coverage within the framework of the feature topic of the prepared issue of the journal “Legal Concept = Pravovaya Paradigma” “Procedural law technologies for preventing offenses and combating crime”.

Connecting the Dots

The Helmholtz Centers operate scientific-technical infrastructures that produce a high volume of digital research data, making Helmholtz a hub for expertise in research data. With the rapid digital transformation and growing volume of data, Helmholtz has implemented relevant policies and engaged in NFDI in various ways to manage and use research data effectively. The Helmholtz Information & Data Science Incubator, in particular the HMC and HIFIS platforms, contribute to these networking activities. The Helmholtz Open Science Office organized several internal forums for Helmholtz members to discuss NFDI, their findings will be presented at the Conference on Research Data Infrastructure (CoRDI). Helmholtz' multifaceted commitment to research data infrastructure is closely related to NFDI activities. The presentation at CoRDI will demonstrate how a large national research data ecosystem can be successfully connected to the NFDI network, highlighting opportunities for future collaboration.

Predictive models of long COVID

The cause and symptoms of long COVID are poorly understood. It is challenging to predict whether a given COVID-19 patient will develop long COVID in the future. We used electronic health record (EHR) data from the National COVID Cohort Collaborative to predict the incidence of long COVID. We trained two machine learning (ML) models - logistic regression (LR) and random forest (RF). Features used to train predictors included symptoms and drugs ordered during acute infection, measures of COVID-19 treatment, pre-COVID comorbidities, and demographic information. We assigned the 'long COVID' label to patients diagnosed with the U09.9 ICD10-CM code. The cohorts included patients with (a) EHRs reported from data partners using U09.9 ICD10-CM code and (b) at least one EHR in each feature category. We analysed three cohorts: all patients (n=2,190,579; diagnosed with long COVID=17,036), inpatients (149,319; 3,295), and outpatients (2,041,260; 13,741). LR and RF models yielded median AUROC of 0.76 and 0.75, respectively. Ablation study revealed that drugs had the highest influence on the prediction task. The SHAP method identified age, gender, cough, fatigue, albuterol, obesity, diabetes, and chronic lung disease as explanatory features. Models trained on data from one N3C partner and tested on data from the other partners had average AUROC of 0.75. ML-based classification using EHR information from the acute infection period is effective in predicting long COVID. SHAP methods identified important features for prediction. Cross-site analysis demonstrated the generalizability of the proposed methodology. NCATS U24 TR002306, NCATS UL1 TR003015, Axle Informatics Subcontract: NCATS-P00438-B, NIH/NIDDK/OD, PSR2015-1720GVALE_01, G43C22001320007, and Director, Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy Contract No. DE-AC02-05CH11231.

Preface

5th International eConference on Frontiers in Materials Engineering and nanoTechnology [ICF-MET-2023] has been held on May 05 – 06, 2023 by Shri Yashwantrao Patil Science College Solankur India. The aim was to provide the common platform for students, professors, researchers and industrialist to present their recent research in the field of Materials Science; Materials Engineering; Mechanical Engineering; Metallurgy; Nanotechnology; Metals, alloys and compounds; Nanofabrication; Properties of Materials; Synthesis, characterization and applications of Materials; Advances in Nanotechnology. It aims at the interaction of knowledge of current and future innovation in the above mentioned field for societal needs. The pandemic situation has taught human beings a lot and now the time to work towards it with new technological ideas. 5th ICF-MET-2023 provides the bridge to fill up the gaps that were essentially found during the pandemic.The response from the scientific community was excellent. The organizers received 95 abstracts; out of which 25 abstracts were rejected. Remaining authors were called to join the conference and share the knowledge with the peers in the field. The five invited talks were arranged where peers from various well known institutions such as KAUST Saudi Arabia; The New College Shivaji University Kolhapur; The LNM Institute of Information Technology Jaipur; Kathmandu University Nepal; participated and all of the participants gave the oral presentations.On the day first, opening ceremony, keynote speech, invited talk and oral presentations took place. Dr. Gholap Sandeep, Senior Scientific Researcher, King Abdullah University of Science and Technology (KAUST), Catalysis Centre, Saudi Arabia gave the keynote on “Iridium Single Atom Catalyst in Glycerol Conversion to Lactic Acid”. It was then followed by an invited talk by Dr. Yadav JB, Scientific Officer, Shivaji University Kolhapur on “Hydrogen a Green Energy Source: Challenges and Opportunities”. The next invited talk was given by Prof (Dr) Subedi DP, Professor of Physics, School of Science, Kathmandu University, Nepal on “Surface Treatment of Handwoven Fabrics by Atmospheric Pressure Dielectric Barrier Discharge”. Then participants gave the oral presentations as per the schedule.The day second was started with the invited talk by Dr. Ashok Chougale, The New College, Shivaji University Kolhapur, India on “Eco-Friendly Nanomaterials: Advancements in Drug Delivery and Wastewater Treatment”. The next invited talk was held by Dr. Unune Deepak, The LNM Institute of Information Technology, Jaipur on “Machining of difficult-to-cut materials using hybrid electrical discharge machining processes: Variants, Capabilities and Research Prospects”. It was further followed by the oral presentations by the participants. At the end, the valedictory ceremony was taken wherein the best presentation awards were also declared.The organizing committee acknowledge the financial and moral support from the Patrons - Hon. A. Y. Patil – Founder & Secretary, SVSPM Solankur; Hon. R. Y. Patil – Chairman, SVSPM Solankur.Beside, we are grateful to Dr. Ashok Chougale, Dr. Vishal More and Dr. Nilesh Pawar, The New College Kolhapur for their expertise and technical assistance.The organizing committee members have taken lot of efforts for this conference.Chairman – Dr Chougale GG;Convener – Dr Patil RB;Coordinator – Dr Tamboli SH;Secretary – Dr Jatratkar AA.The organizers thank all the participants, committee members, experts, reviewers and institute management authority for their mutual understanding and support during the journey of 5th ICFMET-2023. Finally, we would like to take this opportunity to thank the Editorial of IOP: JPCS for their assistance in publishing this issue.

Technologists as policy advisors: A conversation with Dr. Arati Prabhakar

MIT Science Policy Review spoke with Dr. Arati Prabhakar about the role scientists and engineers play in public policy. Dr. Prabhakar is the Director of the White House Office of Science and Technology Policy (OSTP), where she works to harness “the power of science, technology, and innovation to achieve America’s greatest aspirations” [1]. In her current role, Dr. Prabhakar is the President’s Chief Advisor for Science and Technology, a member of the President’s Cabinet, and co-chair of the President’s Council of Advisors on Science and Technology (PCAST). Previously, Dr. Prabhakar served as the Director of the National Institute of Standards and Technology (NIST)and the Defense Advanced Research Projects Agency (DARPA). Between Directorships, Dr. Prabhakar worked to advance innovation in the private sector as an industry executive and venture capitalist, focusing on early-stage semiconductors and cleantech. In 2019, Dr. Prabhakar co-founded Actuate, a nonprofit research and development organization tackling issues in climate change, data security, and health outcomes. We spoke with Dr. Prabhakar about hercareer journey to OSTP and how the White House guides U.S. scientific and technological priorities.

(General Student Poster Award Winner - 2nd Place) Electrochemical Routes for Polymer Upcycling

Approximately 380 million tons of plastic are produced annually, and it is projected to rise to nearly 1.1 billion by 2050 [1]. The largest fraction of such waste consists of polyethylene (PE) and polypropylene (PP), which commonly require energy-intensive methods to achieve depolymerization (such as pyrolysis and hydrogenolysis) due to their remarkable thermodynamic stability. Electrochemical methods are a promising alternative for polymer upcycling as they can utilize renewable energy to create an external potential, overcoming the thermodynamic constraints that the C-C bond cleavage endothermicity imposes on low-temperature polymer conversion. They also offer improved chemical process control by manipulating the electrode potential and minimizing the use and storage of hazardous reagents. Electrochemistry provides a broad range of opportunities for establishing green routes to converting plastic into valuable products.Botte's group is investigating electrochemical approaches to convert polyolefins into valuable products like fuels and fatty acids [2]. Our findings indicate that an electrocatalyst in concert with controlled ionic strength and applied potential enable the selective functionalization of polyolefins and their defragmentation towards target molecules regardless of impurities present in the polymer. In this presentation, we will discuss results of the electrochemical functionalization and deconstruction of low-density polyethylene implementing transition metal electrocatalysts. Acknowledgments: The authors would like to acknowledge the financial support of the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Upcycling of Polymers Program, under Award DE-SC0022307[1] J. E. Rorrer, C. Troyano-Valls, G. T. Beckham, and Y. Román-Leshkov, "Hydrogenolysis of Polypropylene and Mixed Polyolefin Plastic Waste over Ru/C to Produce Liquid Alkanes," ACS Sustainable Chemistry & Engineering, vol. 9, no. 35, pp. 11661-11666, 2021/09/06 2021, doi: 10.1021/acssuschemeng.1c03786.[2] G. G. Botte, "Process for the Electrochemical Up-Cycling of Plastics (US Pending Patent)," U.S. Patent 63040929, 2020.

Computational Search for a Descriptor of Electrocatalysis in Transition Metal-Oxides

Currently, the most effective electrocatalysts for oxygen reduction (ORR) and oxygen evolution reactions (OER) are comprised of noble metal oxides, which bring issues of high cost and scarcity. Discovering earth-abundant alternatives is challenging due to the costly and time-consuming experiments. High-throughput atomistic simulation of catalysts can be an efficient route for enabling the better design and discovery of new electrocatalysts. The efficient use of this approach relies on an activity descriptor that can capture the qualitative and quantitative catalytic trends. In the past, multiple descriptors based on electronic properties have been proposed either reaction-specific or system specific. Therefore, we need a descriptor, which can capture the bonding strength accurately for any sort of reaction or system.In this work, we study the trends of O*/OH* adsorption energies for a wide range of pure metal oxide polymorphs[1] namely rocksalt (MO), corundum (M2O3), rutile (MO2), pentoxide (M2O5) and MO3 in all conceivable oxidation states i.e., +2, +3, +4, +5 and +6 respectively. The main drivers of the adsorption energy are the extent of filling of the bonding and anti-bonding orbitals, along with the spin-dependent coupling strength between the metal-d and oxygen-2p atomic orbitals. This property can be easily captured with the help of crystal orbital Hamiltonian population (COHP). We have observed a strong correlation between the integrated COHP I(COHP) of the bulk system and the adsorption energy, which indicates expensive surface-level electronic calculations can be replaced by bulk-level computations. However, this correlation does not hold on two classes of systems: (i) d0 systems and (ii) systems with significant surface distortion during the reaction. We have considered a different approach to address these systems, where instead of a single bond ICOHP, we account for the summation of the ICOHP around the active site.In search of promising catalysts, we also report tetrahedral systems for 3d, 4d and 5d transition metal oxides, i.e., zinc blende, wurtzite and square planar systems. This will broaden the horizon of possible catalysts along the octahedral systems. We correlate the bulk ICOHP with the surface reactivity of these systems, which highlights the applicability of ICOHP as a universal descriptor across a series of metal oxide systems and guide the design of novel catalysts.This research was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division, Catalysis Science Program to the SUNCAT Center for Interface Science and Catalysis.[1] "Unravelling Electronic Trends in O* and OH* Surface Adsorption in the MO2 Transition-Meta Oxide Series"; Benjamin M. Comer, Jiang Li, Frank Abild-Pedersen, Michal Bajdich, Kirsten Winther, 2022, (ACS J. Phys. Chem C.,)[2] “Predicting O* and OH* Surface Adsorption on Transition Metal Oxides from Bulk Structure”; Benjamin M. Comer, Neha Bothra, Jaclyn Lunger, Frank Abild-Pedersen, Michal Bajdich, Kirsten Winther, Manuscript under preparation.

Photo-Electrochemical Oxygen Evolution Activity in Nickel and Cobalt Antimonates

Renewable generation of fuels via solar energy offers promising pathways towards sustainable energy future. Its deployment hinges on the discovery of electrochemically durable materials with good solar-to-chemical conversion efficiency. Necessary visible spectrum photoresponse from electrochemically stable materials is however quite rare. On the other hand, the oxygen evolution reaction (OER) requires electrodes that are not only catalytically active, but also stable under harsh electrochemical environments. In this talk, we report on and theoretical understanding of photo-electrochemical behavior an amorphous and crystaline versions of Ni-Sb-Ox and Co-Sb-Ox oxide photoanodes discovered via high-throughput experimental screening [1,2]. The newly discovered amorphous phases meet the requirements of operational stability, visible photoresponse, and appreciable photovoltage. Guided by experimental X-ray absorption characterization of these systems we use density functional theory calculations to perform a prototype phase search to identify a broad family of stable and metastable mixed rutile and hexagonal-like phases for other compositions [3]. Detailed Pourbaix analysis of the identified phases show excellent electrochemical stability, consistent with experimentally measured electrolyte concentrations of photoelectrochemical cells. We analyze when he identified phases form favorable oxygen vacancies formation energies under the reducing synthesis conditions which match measured Ni K-edge x-ray absorption spectra. The calculated OER overpotentials for the most active sites decreases with increasing Ni/Co content, which captures the experimentally observed trend. Stable amorphous metal-antimonates photoanodes are important systems for computational understanding of both the structural and catalytic behavior of these complex oxides and elucidating the co-optimization of photo-electrochemical activity and durability. This material is based on work performed by the Liquid Sunlight Alliance, which is supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Fuels from Sunlight Hub under award DE-SC0021266.[1] Zhou, L., Peterson, E. A., Rao, K. K., Lu, Y., Li, X., Lai, Y., Bauers, S. R., Richter, M. H., Kan, K., Wang, Y., Newhouse, P. F., Yano, J., Neaton, J. B., Bajdich, M., & Gregoire, J. M. Addressing solar photochemistry durability with an amorphous nickel antimonate photoanode. Cell Reports Physical Science, 3(7), 100959. (2022).[2] Zhou, L., Wang, Y., Kan, K., Lucana, D. M., Guevarra, D., Lai, Y., & Gregoire, J. M. Surveying Metal Antimonate Photoanodes for Solar Fuel Generation. ACS Sustainable Chemistry and Engineering, 21, 33. (2022).[3] Rao, K. K., Zhou, L., Lai, Y., Richter, M. H., Li, X., Lu, Y., Yano, J., Gregoire, J. M. Bajdich, M., Resolving Atomistic Structure and Oxygen Evolution Activity in Nickel Antimonates, (under review).

Li-Ion and Na-Ion Intercalation in Layered MnO2 Cathodes Enabled by Using Bismuth as a Cation Pillar

Rechargeability of low-cost MnO2 cathodes in aqueous cells has the potential to be an enabling technology for low-cost (<$50/kWh) grid-scale batteries. This rechargeability is imparted by modifying the MnO2 with Bi. In this talk we detail using Bi doping for structural stabilization of MnO2 cathodes for Li-ion and Na-ion batteries in dry, non-aqueous electrolyte. We do this by preparing a series of Bi-doped layered MnO2 compounds, which also contain K ions and crystal water. These phyllomanganates or birnessite-type compounds have the general formula KxBiy-MnO2 • nH2O. The materials are structurally characterized by synchrotron X-ray powder diffraction (XPD) and confocal Raman microscopy. It is found that incorporation of Bi in the structure increases the crystallinity of the material by ordering the interlayer cations. This ordering results in the emergence of a structural superlattice in the material, which has been reported previously for birnessite inserted with other heavy, multivalent cations such as as Sr2+, Ba2+, and Ca2+.We selected three Bi doping levels to study in Li-ion and Na-ion batteries: undoped (y = 0), low-doping (y = 0.013 or 1.3%), and high doping (y = 0.043 or 4.3%). Both doped materials had capacity over 200 mAh/g and allowed for far more stable cell cycling than the undoped Kx-MnO2. The cells made with 4.3% doping of Bi were by far more stable. These cycled at 175-190 mAh/g specific capacity through 100 cycles with a nominal voltage of 2.9 V. Operando XRD experiments to characterize the cathodes within sealed coin cells showed that high-level doping (4.3%) promoted dehydration of the KxBiy-MnO2 interlayer, which had a distance of 6.4 Å. This showed that loss of the crystal water from the interlayer was key to achieving maximum stability during cycling. Lower Bi doping (1.3%) did not cause loss of the crystal water once the cathode was wetted with electrolyte. Previous reports have suggested that Bi doping of 20% results in stabilized Li-ion cycling in layered MnO2. However, these reports involved largely amorphous active material. Our results showed that Bi doping of only 1.3% still provided a large stability benefit, and the high crystallinity of our material allowed it to be structurally characterized, both in the as-prepared state and operando during battery cycling. Results from Na-ion cells will also be presented.Stabilized MnO2-based cathodes that cycle with good capacity and somewhat lower cell voltage than traditional Li-ion cells are a promising strategy for low-cost batteries for the grid. The possibility of using Na as the working ion is also useful for large-scale deployment of batteries to balance renewable power. Acknowledgments This work was supported by the U.S. Department of Energy (DOE) Office of Electricity Delivery and Energy Reliability, Dr. Imre Gyuk, Energy Storage Program Manager. This research used resources of the Advanced Photon Source beamline 6-BM, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. This research also used resources at beamlines 7-BM (QAS) and 28-ID-2 (XPD) of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704.

Characterizing Distribution and Morphology of ZnO Discharge Products in Commercial Alkaline Zn-MnO2 Batteries

During the discharge of alkaline Zn-MnO2 batteries, the dissolution of Zn particles in the anode saturate the electrolyte with zincate, prompting the formation of solid ZnO. Zincate is highly mobile in the electrolyte, giving rise to complex spatial distributions and morphologies of ZnO discharge products. The passivating behavior of ZnO is dependent on its distribution and morphology, as the active Zn particles within the anode must maintain a connection with the electronic network, while also having access to hydroxide ions from the electrolyte.1 Therefore, characterizing the factors that impact ZnO formation is critical to understanding how battery performance is impacted.2 Past attempts to model these batteries fail to adequately predict the behavior of Zn anodes under discharge conditions aimed at simulating real-world use cases.3 This work seeks to better characterize the behavior of Zn anodes in an effort to improve modeling capabilities based on experimental results.4 High resolution synchrotron CT was used to create in situ volumetric reconstructions of anodes from commercial AA and AAA batteries to determine ZnO morphology and radial distribution at various discharge conditions. Through a novel segmentation algorithm, quantitative data show a shift in ZnO radial distribution and microporosity depending on the rate and depth at which the anodes were discharged. High rate discharge leads to ZnO formation preferentially near the separator with a lower microporosity, increasing its passivating characteristics. Microporosity calculations show the discharge products form in two types, namely type I ZnO and ZnO hydrate. The latter type had only ever been reported on planar electrodes, yet it has a significant presence in commercial alkaline batteries discharged under certain conditions.4,5 In addition to a decreased microporosity, the morphology of ZnO also showed increased passivating characteristics when discharging using a continuous protocol. Shells of ZnO form around undischarged Zn cores during a continuous discharge, restricting hydroxide transport to the Zn surface and potentially isolating the core from the electronically conductive Zn network. When using a pulsed discharge protocol, ZnO formed distributed regions of microporous ZnO not adhered to undischarged Zn surfaces, leaving the remaining Zn in good contact with the electrolyte. Developing a more robust understanding of the factors that impact ZnO formation will enable more advanced models to be created. Acknowledgements This research was supported by funding from Energizer Holdings, Inc. We acknowledge collaborators Xiaotong Chadderdon, Matthew Wendling, Andrew Chihpin Chuang, and John Okasinski. This research also used resources of the Advanced Photon Source beamline 6-BM, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

(Invited) Dynamics of Light-Matter Interactions in Plasmonic Optical Cavities for Characterizing Nanostructures Relevant to Energy Conversion and Photocatalysis

Optical cavities are an established means to increase light-matter interactions with a wide range molecules, nanostructures and bulk materials. The use of an optical cavity to increase the likelihood of photon absorption by a material has clear potential for being of value for optical energy conversion and photocatalysis. Furthermore, optical cavities can significantly alter excited state dynamics due to the potential for Purcell effects that increase radiative rates of emission of a given material, molecule, or nanostructure. These dynamic changes can serve as a sensing mechanism of cavity impact to photoprocesses, making characterization tools such as transient absorption and time-resolved emission measurements an effective means to probe the degree of light-matter coupling. Taken a step further, these characterization tools can help establish the degree of light-matter coupling necessary to control excited state lifetimes for a particular purpose or application. Here, we explore the dynamics of nanostructured systems coupled to, or made out of, plasmonic materials. Importantly, plasmonic structures are well-known to serve as a type of optical cavity, and though plasmonic cavities are lossier than their dielectric counterparts, they can also confine light to a small mode volume which is very helpful for increasing photonic interactions with nanostructures. The focus of this talk is on materials and nanostructures of interest for solar energy conversion or photocatalysis, such plasmonic nanoparticles and semiconducting nanoparticles, which are interacting with or functioning as, a plasmonic cavity. The plasmonic cavity can be as simple as a thin metal film that supports a propagating surface plasmon polariton (SPP). We also explore refractory plasmonic systems due to their potential durability and reduced likelihood of melting under optical illumination as compared to noble metal nanostructures. The dynamics of nanostructure photoprocesses as a function of photon energy relative to the cavity resonance is explored in detail and impact on applications is described. Work performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, was supported by the U.S. DOE, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

Operando Measurement of Lithiation Gradients in NMC111-Argyrodite All-Solid-State Composite Cathodes

Achieving the high energy density targets in all-solid-state batteries (ASSBs) will require thick cathodes optimized for full utilization of active material. In composite cathodes with sulfide SSEs, the exclusion of carbon additives makes cathode design to balance ionic and electronic conductivities all the more important. Li-Ni1/3Mn1/3Co1/3O2 (NMC111) is a widely studied cathode material for its high energy density and high working voltage. The lattice parameters of this well-studied structure directly correlate to the amount of Li in the material, allowing for very accurate measurements of lithium-ion concentration gradients (lithiation gradients) throughout the cathode depth.Spatially resolved lithiation gradients in thick NMC111/ Li6PS5Cl composite cathodes were measured using operando energy dispersive X-ray diffraction (EDXRD) on sealed and pressurized ASSBs with varying relative amounts of cathode active mass (CAM) and SSE. Electrochemical impedance spectroscopy (EIS) and transmission line modeling were employed to test the ionic and electronic conductivities of composite cathodes with similar varied CAM and SSE ratios. The balance of ionic and electronic conductivities was found to influence not only the lithiation gradients and utilization of active material in the cell, but also the NMC structural change throughout the depth of the cell resulting in peak bifurcation in the NMC (003) diffraction pattern.Sulfide ASSBs suffer from a large capacity loss on the first cycle due to formation of the cathode electrolyte interface (CEI). To study this interface formation and capacity loss, in situ EIS was performed during the first charge and discharge of the full cell (Li/In| Li6PS5Cl| NMC111/Li6PS5Cl). This piecewise EIS allows us to analyze both time dependent and state-of-charge dependent interfacial processes while the battery cycles with no modifications to cell design. Acknowledgments We acknowledge financial support from the National Science Foundation under Award Number CBET-ES- 1924534. This research used resources of the Advanced Photon Source beamline 6-BM, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

Operando EXAFS to Determine the Mechanism of Bi Dopant at Low Concentration in Rechargeable MnO2 Cathodes

The rechargeable Zn-MnO2 battery system is one few systems in development capable of meeting the extreme cost requirements needed for global integration of battery storage in the power grid. Doping the MnO2 cathode with Bi allows it to cycle reversibly between layered Mn oxides 𝛿-MnO2 and Mn(OH)2, without detrimental formation of Mn3O4. This provides a cathode capacity of 617 mAh/g, which modeling has shown to enable costs below $50/kWh. However, to achieve commercial adoption, cycling stability must be improved. The mechanism through which the Bi dopant improves rechargeability remains largely unknown, and this must be clarified to rationally improve the system. Our previous work has established that the mechanism involves structurally disordered intermediates, and thus characterization techniques based on short-range order need to be used. This talk will demonstrate rapidly collected, operando extended x-ray absorption fine-structure (EXAFS) data collected on MnO2 cathodes with and without Bi dopant. Operando techniques are scientifically powerful as they reduce experimental uncertainty resulting from destructive preparation of samples for ex-situ analysis. In addition, rapid EXAFS collection allows for analysis of the kinetics of Mn coordination changes.Previously, the formation of a disordered 𝛿-MnO2 phase with no diffraction signal was identified during the first charge of Bi-modified MnO2 cathodes.1 In this work, operando X-Ray Absorption Spectroscopy (XAS) was employed to further compare Mn coordination environments in standard and Bi-modified cathodes at points of interest throughout cycling (pristine, intermediate, discharge, intermediate, charged). Specifically, the EXAFS region of the data was used to visualize the dynamic first shell (Mn-O) and second shell (Mn-Mn) interatomic distances during the first cycle. The values throughout cycling were compared with interatomic distances of Mn oxides that have been reported in literature, allowing the data to be used both for “fingerprinting” as a method of identifying the same pristine, intermediate, and discharged phases in both cases. Rapid EXAFS data collection allows for precise analysis of the potentials and states of charge at which these compounds form in each cathode. This portion of the analysis allows for observation of the faster kinetics of changes in Mn coordination in the Bi-modified MnO2 cathode. Furthmore, analysis of the first charge shows that deformation of the Mn(OH)2 discharge product is observed at the same potential energy in both cases, demonstrating that the thermodynamic stability of Mn(OH)2 is not improved in the first cycle of Bi-modified MnO2 cathodes, despite improved capacity. These findings suggest that Bi dopant may primarily act to improve kinetics within the MnO2 electrode rather than enhancing the thermodynamic stability to prevent degradation into Mn3O4. References Andrea M. Bruck et al 2020 Electrochem. Soc. 167 Acknowledgements We acknowledge financial support from the National Science Foundation under Award Number CBET-ES-2044602. This research used resources of beamline 7-BM (QAS) of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704.

Exploring the Impact of Oligomerization on Redox Flow Cell Performance

The redox flow battery (RFB) is a promising stationary energy storage technology due to its inherent decoupling of energy and power, long service lifetime, and potential for low-cost manufacturing.1 While current embodiments are constrained by high upfront cost, nonaqueous RFBs may offer a pathway to cost-competitive energy storage systems through higher energy densities;2 however, this concept is at an early stage and several challenges must be overcome. In particular, the development of stable, high-voltage redox chemistries in conjunction with low-cost, selective membranes is needed to mitigate difficult-to-reverse capacity fade and reduced efficiencies. As such, a range of redox-active organic macrostructures, including oligomers (RAOs),3 polymers (RAPs),4 and colloids (RACs),5 have been described in the peer-reviewed literature. Of specific interest are RAOs, which, like the other macrostructures, can be paired with size-exclusion membranes but exhibit electrochemical and fluid dynamic properties that more closely align with monomers. While this proof-of-concept has been demonstrated,6,7 to our knowledge, few studies have systematically evaluated how the molecular properties of RAOs influence their performance in flow cells.In this presentation, we will describe our efforts to understand how the molecular properties of different oligomers influence their behavior in redox flow cells. To this end, we synthesize and characterize a set of model compounds, ranging from monomers to tetramers, that utilize TEMPO as the redox-active unit. We then assess the thermodynamic, kinetic, and transport properties of these compounds using a suite of voltammetric techniques. Subsequently, we characterize the performance and durability of these compounds in symmetric flow cells via electrochemical impedance spectroscopy, DC polarization, and durational cycling. We perform post-test characterization after the cycling experiments to disaggregate molecular- and cell-level sources of capacity fade. We find that, in general, oligomers with increased size exhibit lower diffusivities while maintaining the facile charge transfer characteristics afforded by the appended monomer. These size-dependent variations in mass transport rates directly translate to differences in cell polarization and cycling performance. Time-dependent capacity fade observed during cycling is confirmed by post-mortem analysis. Broadly, these results align with previously developed relationships between molecular size, electrochemical properties, and flow cell performance; we posit that the principles for functionalization and testing utilized here can be applied to other RAOs with improved stability. Acknowledgements This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. B.J.N gratefully acknowledges the NSF Graduate Research Fellowship Program under Grant Number 1122374. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF. The authors thank Jeffrey Kowalski and Katharine Greco of the Brushett Group as well as Yu Cao and Jeffrey Moore of the Moore Group at the University of Illinois for their contributions to conceptualizing the framework and preliminary testing for this work.

(Invited) Using Molecular Dynamics Simulations to Relate Morphology to Water and Ion Dynamics in Hydrated Ion-Conducting Polymers

Hydrated ion-containing polymer membranes are used as electrolytes in a variety of applications, including in fuel cells and in alkaline batteries. Achieving high conductivity in hydrated, ion-conducting polymers typically requires the hydrophobic backbone of the polymers to be nano-phase separated from the hydrophilic domains so that the ions (protons or hydroxide ions) have well-defined water domains for efficient transport. The ion transport thus depends strongly on the hydration level and on the detailed morphology of the hydrophilic domains. It is often difficult to determine the morphology of these domains experimentally. I will present results from atomistic molecular dynamics (MD) simulations that reveal the domain morphology in various ionic polymers. Increasing water content generally leads to an increase in the characteristic spacing between hydrophilic domains. However, this swelling can be obscured in X-ray scattering due to a loss of scattering contrast between the hydrophobic and hydrophilic domains. The MD simulations reveal that the systems are nano-phase separated, even when X-ray scattering appears to indicate otherwise. Calculated and measured scattering profiles are in good qualitative agreement. I will discuss several methods to characterize the water domain morphology in more detail, including various measures of pore size distributions, surface areas, and fractal dimension. Water and ion diffusivities calculated from the MD simulations follow the experimentally-measured trends in conductivity and are consistent with changes in the nanoscale morphology with changing water content. I will discuss the implications of the results for the future design of ion-conducting polymers for use as membranes in electrochemical devices.This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE’s National Nuclear Security Administration under contract DE-NA-0003525. Figure 1